Force CT低剂量灌注扫描与双能量扫描在肝脏移植术后的应用效果及临床价值分析

Effect and Clinical Value of Force CT Low-dose Perfusion Scan and Dual Energy Scan after Liver Transplantation

目的:探讨Force CT低剂量灌注扫描与双能量扫描在肝脏移植术后的应用效果及临床价值分析。方法:对22例肝脏移植术后患者行Force CT肝脏双能量平扫、低剂量灌注扫描、静脉期和延时期双能量扫描,应用Syngo.Via软件的动态血管成像功能对低剂量灌注图像进行后处理,获得融合后平扫期、融合后动脉期、融合后门脉期、融合后静脉期图像。比较融合后平扫期图像与双能量平扫期图像、融合后静脉期图像与双能量静脉期图像在信噪比、对比噪声比上的差异;测量低剂量灌注扫描辐射剂量与双能量扫描辐射剂量以及两者相结合扫描的总辐射剂量;比较低剂量灌注扫描与双能量扫描的功能特点在肝移植术后的应用效果及临床价值分析。结果:Force CT低剂量灌注扫描融合后平扫期和静脉期图像的信噪比分别为4.36±1.15、8.63±2.16,对比噪声比分别为12.71±2.78、16.83±4.89;双能量扫描平扫期和静脉期图像的信噪比分别为8.53±2.19、16.30±5.15,对比噪声比分别为22.46±5.81、31.13±9.44;低剂量灌注扫描融合后平扫期和静脉期图像的信噪比与对比噪声比均低于双能量扫描的信噪比与对比噪声比,差异具有统计学意义(P<0.05)。低剂量灌注扫描与双能量扫描相结合方案的总容积CT剂量指数CTDlvol值为39.45±2.99mGy;总剂量长度乘积DLP值为951.58±92.49 mGy·cm;总有效辐射剂量ED值为14.27±1.39 mSv。结论:Force CT平扫期、静脉期、延迟期用双能量扫描,动脉期与门静脉期用低剂量灌注扫描,两者相结合的扫描方案比全灌注扫描方案降低了一定的辐射剂量,且弥补了低剂量灌注扫描图像质量较低的不足,这样不仅满足临床诊断需求,还能兼顾两种不同扫描方式带来的特异性优势,更有益于肝移植术后患者的围手术期检查与预后评价,具有广泛有效的应用价值。

Objective:To investigate the effect and clinical value of Force CT low-dose perfusion scan and dual energy scan in liver transplantation.Methods:22 cases of patients after liver transplantation underwent Force liver dual energy CT scan,low doses of perfusion scanning,venous phase and delayed time double energy scanning,dynamic vascular imaging function of the Syngo.Via software was used to post-process low dose perfusion image to obtain images of plain scan after fusion,arterial phase after fusion,portal phase after fusion,and venous phase after fusion.The difference of signal-to-noise ratio(SNR)and contrast noise ratio(CP)between plain image and double energy plain image,venous image and double energy venous image after fusion were compared.The radiation dose of low-dose perfusion scan,dual-energy scan and the total radiation dose of the combined scan were measured.To compare the application effect and clinical value of low dose perfusion scan and dual energy scan after liver transplantation.Results:The signal-to-noise ratio of Force CT low-dose perfusion scan after fusion was 4.36±1.15 and 8.63±2.16 in plain and venous phase,respectively.The contrast noise ratio was 12.71±2.78 and 16.83±4.89,respectively.The signal-to-noise ratio was 8.53±2.19 and 16.30±5.15,respectively.The contrast noise ratio was 22.46±5.81 and 31.13±9.44,respectively.The signal-to-noise ratio and contrast noise ratio of images in plain and venous phase after low-dose perfusion scanning fusion were lower than those in dual-energy scanning,and the difference was statistically significant(P<0.05).The total volume CT dose index(CTDlvol)of low-dose perfusion combined with dual-energy scanning was 39.45±2.99mGy.The total dose length product DLP was 951.58±92.49 mGy·cm.The total effective radiation dose ED value was 14.27±1.39 mSv.Conclusions:Force CT dual energy scanning is used in plain scanning,venous phase and delayed phase,and low-dose perfusion scanning is used in arterial phase and portal phase.Compared with total perfusion scanning,the scanning scheme combined with the two reduces the radiation dose to a certain extent and makes up for the low image quality of low-dose perfusion scanning,which not only meets the needs of clinical diagnosis.It can also take into account the specific advantages brought by two different scanning methods,which is more beneficial to the perioperative examination and prognosis evaluation of patients after liver transplantation,and has a wide and effective application value.